US Navy railgun test fire. This is an extended-footage version of the official Navy video.

Rather than relying on an explosion to fire a projectile, the technology uses an electomagnetic current to accelerate a non-explosive bullet at several times the speed of sound. The conductive projectile zips along a set of electrically charged parallel rails and out of the barrel at speeds up to Mach 7. The result: a weapon that can hit a target 100 miles or more away within minutes.